SpringBoot使用JDBC获取相关的数据方法

<dependencies>    <dependency>      <groupId>org.springframework.boot</groupId>      <artifactId>spring-boot-starter-jdbc</artifactId>    </dependency>    <dependency>      <groupId>com.h2database</groupId>      <artifactId>h2</artifactId>    </dependency>  </dependencies>

package com.example.kane.Model;public class Customer {  private long id;  private String firstName, lastName;  public Customer(long id, String firstName, String lastName) {    this.id = id;    this.firstName = firstName;    this.lastName = lastName;  }  @Override  public String toString() {    return String.format(        "Customer[id=%d, firstName='%s', lastName='%s']",        id, firstName, lastName);  }  // getters & setters omitted for brevity}

package com.example.kane;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.CommandLineRunner;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.boot.web.client.RestTemplateBuilder;import org.springframework.context.annotation.Bean;import org.springframework.jdbc.core.JdbcTemplate;import org.springframework.scheduling.annotation.EnableScheduling;import java.util.Arrays;import java.util.List;import java.util.stream.Collectors;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.web.client.RestTemplate;import com.example.kane.Model.Customer;@SpringBootApplication//@EnableSchedulingpublic class RestfulWebService1Application implements CommandLineRunner{    private static final Logger log = LoggerFactory.getLogger(RestfulWebService1Application.class);  public static void main(String args[]) {    SpringApplication.run(RestfulWebService1Application.class, args);  }  @Autowired  JdbcTemplate jdbcTemplate;  @Override  public void run(String... strings) throws Exception {    log.info("Creating tables");    jdbcTemplate.execute("DROP TABLE customers IF EXISTS");    jdbcTemplate.execute("CREATE TABLE customers(" +        "id SERIAL, first_name VARCHAR(255), last_name VARCHAR(255))");    // Split up the array of whole names into an array of first/last names    List<Object[]> splitUpNames = Arrays.asList("John Woo", "Jeff Dean", "Josh Bloch", "Josh Long").stream()        .map(name -> name.split(" "))        .collect(Collectors.toList());    // Use a Java 8 stream to print out each tuple of the list    splitUpNames.forEach(name -> log.info(String.format("Inserting customer record for %s %s", name[0], name[1])));    // Uses JdbcTemplate's batchUpdate operation to bulk load data    jdbcTemplate.batchUpdate("INSERT INTO customers(first_name, last_name) VALUES (?,?)", splitUpNames);    log.info("Querying for customer records where first_name = 'Josh':");    jdbcTemplate.query(        "SELECT id, first_name, last_name FROM customers WHERE first_name = ?", new Object[] { "Josh" },        (rs, rowNum) -> new Customer(rs.getLong("id"), rs.getString("first_name"), rs.getString("last_name"))    ).forEach(customer -> log.info(customer.toString()));  }}

package com.example.kane.Model;import org.springframework.boot.CommandLineRunner;import org.springframework.core.annotation.Order;import org.springframework.stereotype.Component;@Component@Order(value=1) //因为可能有许多事情要做，Order 可以根据大小，判读执行的顺序public class run_after_application implements CommandLineRunner{  @Override  public void run(String... args) throws Exception {    // TODO Auto-generated method stub    System.out.println("-----------------------");  }  }

//为Bean创建一个JdbcTemplate以供使用//再没配置DataSource的情况下 springboot提供了 一些嵌入式的数据库支持，上面的例子使用的就是H2数据库，是一个内存的数据库

//构造的时候传入一个 DataSource，来获取链接//JdbcTemplate Spring boot默认链接的是H2 database，

package com.example.kane.config;import org.apache.commons.dbcp.BasicDataSource;import org.springframework.beans.factory.annotation.Value;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import javax.sql.DataSource;@Configurationpublic class db_config {  //这个类是一个Config类    @Value("${db.driver}")    private String DRIVER;    @Value("${db.password}")    private String PASSWORD;    @Value("${db.url}")    private String URL;    @Value("${db.username}")    private String USERNAME;    @Bean    public DataSource dataSource1() {      BasicDataSource dataSource = new BasicDataSource();      dataSource.setDriverClassName(DRIVER);      dataSource.setUrl(URL);      dataSource.setUsername(USERNAME);      dataSource.setPassword(PASSWORD);      return dataSource;    }}

# Database# mysqljdbc连接驱动db.driver:com.mysql.cj.jdbc.Driverdb.url:jdbc:mysql://localhost:3306/testdb.username:rootdb.password:root

<dependency>  <groupId>commons-dbcp</groupId>  <artifactId>commons-dbcp</artifactId>  <version>1.4</version></dependency><dependency>  <groupId>mysql</groupId>  <artifactId>mysql-connector-java</artifactId>  <scope>runtime</scope></dependency><!-- 需要用到commons-dbcp连接池，以及连接mysql使用的drver-->

@Autowired  JdbcTemplate jdbcTemplate;  //下面是加载了数据库的配置。只需要增加这个  @Autowired  db_config db_config;

SELECT * from customers;------------------------1  John  Woo2  Jeff  Dean3  Josh  Bloch4  Josh  Long

# databasespring.datasource.url=jdbc:mysql://localhost:3306/testspring.datasource.username=rootspring.datasource.password=spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

spring: datasource:  url: jdbc:mysql://localhost:3306/test  username: root  password: root  driver-class-name: com.mysql.cj.jdbc.Driver